Fig. 3: Shoot BR is a limiting factor for root biomass growth and its metabolic balance.

a Scans of grafted plants showing scion/rootstock of WT/WT, WT/cpd, cpd/cpd, and cpd/WT (8-week-old grown in pots, after washing with water to remove the perlite grains, see scheme in Fig. 1a). b–d Biomass of plants as in (a). b Shoot fresh weight (FW), c root FW and d root dry weight (DW). Note the full rescue of cpd root biomass by the WT shoot and the poor biomass of the WT root when grafted to the cpd scion. In boxplots, the center corresponds to the median, the lower and upper hinges represent the first and third quartiles, and the whiskers extend to the largest and smallest values within 1.5× the IQR from the hinges. All data points are plotted individually. Different letters indicate values with statistically significant differences (n: WT/WT = 19, WT/cpd = 19, cpd/cpd = 2, cpd/WT = 11, p ≤ 0.05). e Metabolite levels in the root depend on BR signaling in the shoot. A heatmap showing metabolites that are significantly different among WT/WT, WT/cpd and cpd/cpd^un. (n = 6, p ≤ 0.05). FC fold change. *p ˂ 0.05, **p ˂ 0.01, ***p ˂ 0.001.